Saving Old Seagulls

Horsley-Anarak wrote:"At the end of the day , after all the hassle surely it is cheaper in the long run to buy a new one."

Which one would i buy, Mariner or Yamaha possibly a Mercury

Seagulls are a truly hideous piece of engineering ( we all know that).

I think that you might be missing the point twostrokenut.

If all I wanted to do was move a boat on water, I would not even think of using a rubbish 70 year old Seagull.

H-A

Crossed wires HA (pardon the pun) , when I said buy a new one , I was meaning a new coil , not a new (or even modern) outboard , new coils are available , and certainly work out cheaper than a rewind.
And where did I say Seagulls were a truly hideous piece of engineering , I'm quite fond of some models , just that I prefer dabbling with some of the rarer british motors.

Andy.

New coils for SD or Marston engines are not available.

The shorter coils are available, but they cost £45.00 plus postage.

The wire needed to rewind a seagull coil ( if you buy it by the Kg ) would cost less than £2.00.

The only additional cost would be the labour (that can normally be paid for in beer) .

When you have a small collection of seagulls and in Timberman's case 5 duff coils, the thought of buying 5 new coils will soon make you less interested in seagulls.

There is no reason that with a little bit of application we should not be able to rewind coils.

I fully understood what you meant about buying a new one.

H-A

no no no.....

seagulls are that mystic and wonderful creation that permits one to spend hours in the shed / garage, happily grumbling away about whitworth this and 20 thou that ..and why doesn't this bloody screw / bolt give up after 1000 degrees of heat ...and I REALLY DO need to get an impact screwdriver ....

having swapped a 'good' coil for my early BurmaBright SJP's 'dead' one, 2 pulls on the cord, and off we went ...it was bliss

I do admit that having to repalce 5 coils doesn't get me £££££ THAT excited ....but neither does trying to rewind one ...
...How many miles was it ???

anyway the SD (naval) is now utterly reliable (plug and HTlead ) and pushes along at a spanking speed ...better than a 5 blade CPC
this was of course timed by Small Boy between 2 significant trees on the river using the stopwatch feature on my mobile

the other side to this of course is that H-A rather enjoys sniffing the meths

but even given the previous, still happy to tow gleaming non-functional exhibition pieces....with my aching 1941 SD ... back to safe harbour

Neal Your SD would not run, I thought it was a forty plus with a clutch that towed me.
40 tpi spent most of his time at the Thames meet getting you out the reeds when your SD would not go.

HID would not have needed a tow if she had not broken my AC.

I am well up for an SD on SD race on the Thames before the season ends.

Dont blame my olduns that needed a tow, will also give you an ON race winner buys lunch.

Or we could do the pre Lerryn ( I have wet weather gear meet ) just to see which engine might go to the only recognised race in the UK (RNLI was it a race ?).

H-A


,

twostrokenut wrote:The correct method is to have your coil and condensor tested on a proper testing unit , these simulate RPMs for breakdown , however even a proper tester cannot simulate heat build up and the asscociated breakdown of components.
At the end of the day , after all the hassle surely it is cheaper in the long run to buy a new one.

Andy, I've already planned the reliability/burn in test for when I finish my first rewind! Pretty trivial to rig up a variable bench pulse generator with a power FET and a Schottky clamping diode along with a DC supply and simulate any RPM for as many times round Bermuda as I wish until it either pops or I get bored. The heat cycling for testing electronic kit in my workshop has been done for years using a hair dryer. If it has a large thermal mass I get the paint stripper gun out!

I don't currently need to rewind one of these since I have spares but Just like Allan says it's a challenge! And I just love reverse engineering problems. As I've said earlier some would likely stump up the price of a rewind exchange unit. Few would stump up for a new old stock item. Others will have fun and enjoyment bringing a coil back to life............horse and courses.

I'll have a dead TC Villiers MK1 in meths by tomorrow afternoon........ If I trash it taking it apart I'll be round to see you Neal!


Peter

well Peter I seem to have a few candidates ...

H-A, memory like an elephant,
quite correct it was the 40 + that saved the day ....and the embarrasment of a foliage encrusted bowsprit (delightfully arranged of course) meant I got the SD fettled a bit sharpish

YUP to an SD vs SD challenge .... even ON on ON, head to head, before the weather closes in

when and where ??

40TPI is the mathematics wizard..he can work out the appropriate handicap calculation for differences in hull form and weight, flow characteristics, wind resistance...and how many extra Klingons are needed 'cos the Di-Lithium crystals canna take it

Mmmm. Been looking at the bobbin. Can the bobbin slide of the core? Why buy new wire if the old wire is still good? Is that for a wipika coil?

HT coils I have found faulty was usually the thin wire burning off near the "outlet" tag. Sometimes a sharp edge somewhere on the tab causes the coil to arc there, and eventually melt through the secondary wire. I have fixed many a transformer this way: Remove the outer layer of insulation, get to the first layer of the secondary, scrape and clean the wire end nearest the tag, check resistance over primary. If you get good resistance then you've found your trouble, unwind a turn or two, resolder the secondary to the tab, make sure you leave no sharp edges, and bob's your uncle. Of course I have no idea where the actual tab is for the HT outlet on these coils! Usually its as far from the primary as possible on the outside of the coil. Of course if this is not your problem, you will have to unwind. Unwind a layer at a time or until the broken wire comes off by itself, chances are the damage is in the outer layer. If the coil have burned (shorted) the resistance will be much less than usual, in this case the whole coil needs replacing.

The insulation layer is not as much insulation as to prevent the coils of thinner wire to slide into the thicker wire. Almost anything can be used for insulation. Wax paper/tape comes readily to mind. The windings need to be in the correct direction else the voltage me be out of phase, I think its the same direction as primary, but can't recall offhand and I am too lazy to google, search "autotransformer winding" or something or check your now opened up transformer.

If the bobbin can slide off, jiggle a steel shaft in there. Clamp it in a vice and use a drill or Dremel with a shaft to unroll the old coils unto it. Once done, measure the resistance over the length of wire. If the resistance is highish, dunno, I've heard 4000ohm mentioned for these coils, then your old wire is ok for re-use. I may be wrong in removing the wire, because it may be glued in, but that is seldom the case except for the outer layer or two, because of sticky glue in which case you can soak it off. Do not use anything that dissolve varnish though . Usually coils that gets too hot have the winding's insulation melt a slight bit and then stick to each other, thus you will have plenty of breakages, so just cut it off.

For secondary wire, an old car coil is usually easy to open. (Scrap yards have plenty, of course they will sell it as "good" condition.) Just bend the lip of the can open You will find oil and plenty of wire inside. It may be too thick though, but it should be correct. The windings on a car coil is very easy to unroll, since it sits in slippery oil! If you are clever you can unroll straight from the car coil unto the seagull core. Precise winding should not be a problem, as long as you don't bunch up the wire too much. If you can add more windings than original. You will have a higher voltage, which should give you a better spark! I don't think you will be able to "overwind" the coil so that HT breakdown will occur. The voltage will in any case vary much by how strong your flywheel magnet is and how close it comes to the coil. "Charging" the magnet with a drill is a typical application of spark strength to magnet power.

If you can figure out the primary voltage, it will be easy to work out how many secondary turns is needed. For a typical 12V coil, to get a 12000V spark you need 1000 turns of secondary for every turn of primary. If you want to be daft and want to reduce the number of secondary turns, increase primary voltage. Perhaps a 12V battery in series with the points? Heh heh heh! Or else a stronger magnet, or remove a coil or two from the primary.

Hmmmm

noticed that H-A doesn't seem to have taken up the offer to run head to head races down the leafy (for the moment) Thames

'secially seeing as I've fettled up my gleaming masterpieces ...thoroughbreds through and through ...to take on any challenger

well, 'spose when you hold the title of RNLI World Champion for PROPER displacement hulls, it will tend to put lesser mortals off

Ahhh well, such is the price of victory << leans comfortably back on the laurels>>

'cept for the small item <<discrete cough>> of a few coils

V sorry wood man, have been in shed.

Bring it on, boats and engines are waiting, previous venue would be good.

Perhaps our social secs should touch base.

SD now has a welding spark.

H-A

I use rubbish 60 year old seagulls with the dreadful original villier electrics, lots of very long runs, never had any troubles, only occasional fouled plug and a couple of times a year I clean the carbie, but I suppose that is what old rubbish seagulls are about.

Wood Man it looks like the last of the Seagull outboards to have used Birmabright aluminium alloy was probably the SN & SNP pre war motors,
though only 1 has surfaced, so we can't be sure it wasn't just to use up the last of the Marston stockholding.
Perhaps H-A could get one of his mates to check out exactly what his SD & ON were cast from.

It seems that all Seagulls from 31 to the early 60's had polished lower units, (the other Charles should be able to tell you exactly when the 3 guys in the polishing department were sacrificed in the cost cutting war against the Japanese & American imports)

I dont know if its much use, but i remember my farther using an adaption to my mothers old hand cranked sowing machine. He would be counting out loud as he cranked the handle, winding the fine wire onto the spinning coil. I have asked him if he still has the adaption but he stated my moter baned him from ever using it again. but he clames it works. Back in the early 60s Matchless coils gave simalar problems .

Horsley-Anarak wrote: The pick up is soldered to a band of windings about 3mm wide, when the soldering takes place the rest of the coil is protected by a mica patch.
H-A

Well Allan you prompted me to catch up........

Click to enlarge.....

Stripped the plate to get to the coil.......


MK1 Villiers opened up.........

Ooh err sticky mess.........rank smelling ( decomposing?) shellac, half dissolved in meths. But we can see the basic technique that was used to terminate the end of the winding. This one has a 12mm round tinned metal disc contact soldered at the end of the winding, held in place with cloth and having both cloth and mica pads underneath. No sign of any shorted turns used as solder pad.



These are the main cloth, mica, wire and metal disc components used to terminate the end of the winding prior to closing off the assembly with the outer tube and adding the external button contact. (The extra , thicker wires, just visible, are for strain relief purposes in the end connection.)


And yes there is a hell of a lot of 3.5 thou enamelled to take off! Coil now back in the meths to soften it up some more... then onto turns calculation after each layer is taken off.........


But this might make it easier putting it back ....


Had a chat with the magneto fairy and found this in the back of the estate this morning.......


Peter